In the prior art, a slide-type discharge apparatus having a plate-like valve body (partition plate) which slides in a horizontal direction so as to be orthogonal to an input pipe at the lower end of the storage part provided almost vertically is well known as a material discharge apparatus for a powdered or granular material provided at the lower end of the storage part storing a powdered or granular material. The slide-type discharge apparatus is designed in such a manner that the plate-like valve body is slidably moved in a valve casing having an opening communicating with the input pipe to open or close the input pipe, thereby discharging a powdered or granular material. There has been such a problem that a powdered or granular material gets stuck between the plate-like valve body and the opening of the valve casing and further operation failure and damage are caused by sticking of material.
Patent Literature 1 discloses a valve system for a powdered or granular material being connected to a pipe connected to a hopper and having a slant inlet cylinder and a rotary cylinder with a bottom rotatably fitted to the inlet cylinder from below so as to be concentric with the inlet cylinder but not to slidably contact the inlet cylinder. In the valve system, the rotary cylinder is rotated at a position which covers a downward opening of the inlet cylinder and a position which does not cover it, thereby controlling material discharge (flow). In addition, the valve system has a gap which is slightly larger than the particle diameter of the material between the rotary cylinder and the inlet cylinder, thereby preventing breakage of the material and rotating the rotary cylinder smoothly.